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MET ONE R4800 and R4900 – Remote Air Particle Counters

The MET ONE R4800 and R4900 series remote air particle counters are affordable, reliable and provide accurate data in particle monitoring systems. A compact design with flexible sizing, flow rate and communication options address the specific needs of cleanroom operations in pharmaceutical, semiconductor, hard disk drive and flat panel display industries.

Easy Integration

  • MET ONE R4800 series remote air particle counters use standard RS-485 serial communications
  • MET ONE R4900 series remote air particle counters use industry standard 4-20mA interface
  • Stainless steel enclosure compatible with most process environments
  • Compact size for easy mounting with a vacuum source, DC power & communication line

Data Management

  • MET ONE R4800 & R4900 counters respond to simple ASCII command instructions, including start, stop and report counts, send location number, etc.
  • Reporting data includes counter status & particle counts in two size ranges
  • Multiple display options via continuous monitoring feature (Particle Vision® Online & CIMScan® software


  • User-programmed alarm level detects high counts on first channel triggering an alarm
  • Auto alarm reset at start of the next count cycle
  • Long-life laser technology for superior performance & extended service life
  • No fan allows proximate placement to sensitive processing areas


  • Sensitivity ranges of 0.5um & flow rates of 1.0 cfm
  • Onboard status indicator sets signal at connector for alarm Stay resident RS-485 configuration programming (count/hold times, alarm level/delay & scaling) maintained through power cycles
  • Sensor resistant to  vaporous hydrogen peroxide (VHP)